Minolta (Maxxum/Alpha) 9000 AF: Removal of the mirrorbox/assembly, investigating the aperture issue, replacing the sticky damper in the shutter unit

BMbikerider said:

One question though, these were also known for having leaking LCD windows. Can they not make these leak proof? This problem also affects The Nikon F4 as well and I had to stop using one because the LCD went blank after a few years in my use.

Click to expand...

With the F4 you can replace the LCDs quite easily yourself or have someone do it for you, the smaller one in the camera and the larger one in the DP-20 viewfinder, see my posts on this here.

Or you can replace the DP-20 completely, replacements are easy to get on eBay, for example.

BMbikerider said:

I would love to work on something like this but my engineering and repair skills are with much larger pieces of equipment. If it doesn't involve torque wrenches or an assortment of spanners from 10mm to 26mm I am struggling.

Click to expand...

But the principle should be the same, just scaled on a larger scale.

"This is a 3M florad chemical product. It is used mostly in the camera repair business to prevent oil contamination on the electro magnet surfaces .
Cameras like the older SLR series , canon AE1 series,Nikon , Olympus OM10 series , Minolta Xseries cameras.
It is also used on lens diaphragm assemblies .
A small drop on the cleaned surfaces of the magnet face and pallet will prevent the migration of any grease or oil to that surface.
I sell the barrier in small 5ml plastic pipette applicators. Enough for hundreds of applications as you only use a tiny drop."

This is interesting. Was looking at the stuff linked in this thread and thought that one listing sounded like a familiar problem. Guess the AE1 guys might have more writing about on what causes the electromagnet surface contamination problem and how to solve it.

Looking into whatever "3M florad" is, i'm fairly sure its a typo for Fluorad... which itself I think is an outdated brand name for 3M's Fluorinert stuff? Or specifically a fluorinated conformal coating.

3M Novec 1700 describes itself as "EGC-1700 dries to a thin transparent film with excellent anti-wetting, anti-stiction, anti-migration, and anti-corrosion properties..." as well as being the replacement product for a range of Fluorad coatings. And from only £2956 a 5kg jug! There's probaby similar stuff out there that may be available in smaller quantities but it's annoying to try find info on this sort of stuff. I think the normal thing to do is call a sales rep and also own a big factory.

I'm tempted to just buy that stuff from ebay but the shipping is a bit steep from the states. I'm also still convinced the degrading old coating was the source of the problem more than oil contamination.

I still don't understand how oil can get on the contact surfaces of such magnets in cameras or where the oil comes from.

Could it be the precipitation of vapors from oil or other chemicals that collect in the camera?

Capillary flow, I'd guess?

Man that conductive tape stuff arrived and hasn't been that amazing. Was hell to install since it prefers to stretch more than it comes off the backing, and after alot of fiddling and adding shims I had all the segments on... but then putting the top back on knocked half of them out again. Flexing the top cover while installed has the segments appear and disappear. Frustrating stuff! Actually after letting it sit a bit they came back but then went out again pushing on the top cover. I'm surprised that influences stuff. Maybe somethings colliding that shouldn't be... it's gonna be a frustrating thing to troubleshoot...

ogtronix said:

Capillary flow, I'd guess?

Click to expand...

But there would have to be a lot of oil on the move and overcoming barriers. I don't think that's realistic.

ogtronix said:

Man that conductive tape stuff arrived and hasn't been that amazing. Was hell to install since it prefers to stretch more than it comes off the backing, and after alot of fiddling and adding shims I had all the segments on... but then putting the top back on knocked half of them out again. Flexing the top cover while installed has the segments appear and disappear. Frustrating stuff! Actually after letting it sit a bit they came back but then went out again pushing on the top cover. I'm surprised that influences stuff. Maybe somethings colliding that shouldn't be... it's gonna be a frustrating thing to troubleshoot...

Click to expand...

You know, I'm doing everything I can for research

Should I send you the part from my trainings 9000 if I find it?

Or would you rather work on a replacement?

Thanks again for the offer but i've got a spare LCD in the other camera. I was tempted to try swap it out since i kinda half-dissolved the polarizing film with acetone on this first one, but from inside the viewfinder I can't see anything wrong with it since it's on the back side.

Anyways I got it back together and working for now. That was alot of fiddling!


The problem was that the top cover was pressing on that flat flex cable to the LCD, and even small amounts of flexing were breaking the connection with that funny anisotropic conductive tape. I tried alot from adding more thin bits of rubber under that retaining bar, rubber in special places, sliding the rubber up and down on the double sided adhesive, moving the whole LCD unit back and forth, even snipping a corner of that flex cable off so there was less to collide with. I was also considering slitting it up to that hole in the middle to make it less... monolithic... so it could hopefully flex a bit more without tugging, but that felt it was getting a bit too destructive.

In the end what worked was removing the rubber entirely, go figure, but also sticking the cable down to the top of that IC with double sided and then some kapton tape to try anchor it a bit better. Thinking about it now, maybe a blob of epoxy on the bar to really fix things in place so the cable can't move where it's connected would help... which actually come to think of it is what the service manual recommends, I think. Seems extreme and tricky to reverse if it doesn't work, however.


Also, to get the tape off the backing without it stretching so much, peeling it off at a sharp angle like this helped.

Anyways we'll see how long this lasts or if something isn't working that I haven't tested yet. I feel dumb old cameras like this will never be truly solved forever - they're kinda badly designed, cobbled together, and rushed to market to begin with. But hopefully it'll stay working for at least a few months.

Precision work!

Do you use magnifying glasses for this?

I don't, no. I guess the times i've wanted want to see something up close, like the lettering on an IC, I've taken a phone photo. There's been a couple times with this stuff where i've seen dust or bits of fluff in photos I took after the fact though, so maybe some day I should get a nice loupe or something. It's a shame dental loupes are so obscenely expensive, I've heard they're impressive.

I use these magnifying glasses, they can be worn with prescription glasses, are simple and robust.

I have four interchangeable lenses (2.5, 4.0, 5.0 and 7.0 x)

Well that thing worked for a bit but it's just abruptly lost half its segments over the last couple hours while just sitting there. Temperature change or maybe the tape holding down the LCD cable sprung loose? That anisotropic tape is a little disappointing...

So I the options I can think of are:

• Try re-seat/ compress it till it works then dollop epoxy around to make sure nothing important can move. Seems risky and hard to reverse.
• Remove the tape and see if the right amount of rubber pads under the pressure bar can get it to sit reliably in contact. It worked the first time around till I disturbed things with the recent repair.
• Same as above but with epoxy dollops once in place.
• Cut the whole-ass LCD assembly off, scratch back the kapton over the FFC's traces, do the same with the working LCD module from a donor camera, and solder them together. Quite extreme and I suspect nudging around the donor LCD while doing this would probably break it's old brittle heat seal connection.
• I start a new project where I throw the camera into a lake.

Is it possible that the contacts on which the conductive rubber rests are contaminated or corroded?

I had observed the latter with the Nikon F3, but the digits disappeared gradually and not suddenly, like with your 9000.

Andreas Thaler said:

Is it possible that the contacts on which the conductive rubber rests are contaminated or corroded?

I had observed the latter with the Nikon F3, but the digits disappeared gradually and not suddenly, like with your 9000.

Click to expand...

I doubt it. I think it's just the way that anisotropic conductive tape works where whatever connections are forming are quite fragile, the datasheet recommends mechanical support of the bond, and unfortunately the way this camera is designed both puts changing strains on the connecting cable and doesn't retain it super securely. Which is possibly the cause of the original failure and why the service manual suggests putting epoxy on stuff as part of the repair.

I keep getting jumpscared by the way the camera doesn't let you do a depth of field preview when it's in its 'winding the first few frames' mode after opening and closing the back, along with the 'reset ISO mode' locking things after replacing batteries. This thing really might end up in a lake if the aperture problem returns so soon.

The official service manual steps for repairing the LCD involve an 'elastic connector' which I assume means an elastomeric connector aka zebra strip. I got a friend to type out the Japanese in the parts list, it's just listed in English as "Connector," and エラステイコネクター is just the katakana for erasuteiku konekutaa. Which is mildly amusing but doesn't elucidate much.


I'm getting deja-vu, I think i've said most of this before... either way I can't find any kind of source for 0.3 or 0.5mm thick elastomeric connectors. I don't even know if they make them that thin normally. I was hoping that anisotropic conductive tape would stand in as something similar, but its connections get broken too easily by any kind of movement even when held under pressure.

What I might try is cutting a sliver off of a bigger block of elastomeric connector ripped out of a Lesser Device. I remember trimming one down height wise in the past and it working, but hell if I remember what it was for... but cutting such a particularly narrow wafer of rubber and having it remain flat seems tricky. Maybe freezing it beforehand, or really freezing it with dry ice, could help.

I don't understand why you want to replace the elastic connectors ("Leitgummies" in German) - are they lost or totally broken?

The original connection is a heat seal connector, I think. They're mentioned in this wikipedia article. It's a kinda connection made with a weird and hard to source tape that you set by squashing the connection with a heated bar at a particular temperature and a particular pressure that adheres it rigidly and makes said connection. I had an analytical balance years ago that was suffering some missing lines on its LCD from one of those connections failing, that I made worse with an attempt to repair it because I habitually just can't leave stuff alone. I think the specific temperature and pressure is determined through trial and error as part of a mass manufacturing process, but for repair technicians I guess they supplied them with an alternate style of connector since the equipment for a dialed in heat seal setup wouldn't be feasible.

I was hopeful that 3M anisotropic tape would've worked as some kind of modern room temperature and more forgiving alternative to a heat seal connector, but i'm not particularly convinced.

Also lol current era search engines... with "Leitgummies" I had to fight it to not show me either cannabis gummies or the harvestmen arachnids, leiobunum.

@ogtronix

Is it your ambition to find your own solutions instead of original spare parts?

An exciting thing.

I don't know if original spares even still exist. Did Sony not liquidate them? Or if they even make sense since most of the problems with these cameras are from degrading materials or parts that were never sufficient to begin with, so a replacement part probably wont solve much.

Really the attitude i'd have towards these cameras is less about historical preservation and more about them being a currently available resource and fun to play around with. There were guys out there attempting PCB replacements with SX-70 Polaroid cameras, and I don't know if that went anywhere but I absolutely admire the intent... In the end this is all just rapidly degrading junk designed to hit quarterly margins. In another 40 years the plastic will probably be too brittle to ever consider seriously using. It'd be nice if some museums kept good examples in stock as historical reference, but as far as i'm concerned these are just things that currently show up on ebay for £40 or less in auction. And deservedly too for all the problems they have.

Sometimes I wonder if the power of old marketing still has a hold over people too. I mentioned 'fuzzy logic' to my uncle a bit ago as a joke after he brought up AI garbage... and he kinda lit up. Like i'd hit his MKUltra trigger phrase, and he started reciting whatever 1990s garbage marketing phrases he'd ingested back then.

ogtronix said:

I don't know if original spares even still exist. Did Sony not liquidate them? Or if they even make sense since most of the problems with these cameras are from degrading materials or parts that were never sufficient to begin with, so a replacement part probably wont solve much.

Click to expand...

I get spare parts from abandoned photo equipment of the same type.

Obviously parts age differently, even if they are the same.

Unfortunately, this does not seem to be the case with the dampers in the shutters of the Canon T90 and Minolta 9000 AF, they rot at the same time.

But otherwise you have a good chance of finding replacements, I think.

Andreas Thaler said:

I get spare parts from abandoned photo equipment of the same type.

Obviously parts age differently, even if they are the same.

Unfortunately, this does not seem to be the case with the dampers in the shutters of the Canon T90 and Minolta 9000 AF, they rot at the same time.

But otherwise you have a good chance of finding replacements, I think.

Click to expand...

In the case of this LCD the repair steps involve adding a new part, that 'elastic conductor,' to replace the old heat-set conductive adhesive.

I've managed to get the LCD working again. I'm jumping the gun a bit with this post since I've not put the top back on yet, but i'm passing time as that epoxy cures.

First step was trying to find a zebra strip. I though I had some LCD modules somewhere but I couldn't find them... then I remembered i've got a bunch of junk cameras that have LCD panels in them.


The Minolta 7000i is a pretty lame camera and not currently particularly valuable. Plus i'm curious about how different it is to the 7000. There's always the risk a movie prop or some youtuber might make these worth a fortune to cosplayers some day though.

Getting inside of it was tricky since there's plastic tabs holding alot of the case on. I was convinced the grip part was separate and had to come off for most of it, but it turns out it's integral to the whole body. There's a secret secret hole the red arrow is pointing to that holds the top on, but I don't have a long and narrow enough screwdriver to reach it so the top just got ripped off. To remove the mirror box you need to pull the rubber grip off too, which is of course very brittle now.

The whole thing is quite baffling and awful, fully wrapped in soldered together PCBs that cover and obscure various screws. I'd say without a service manual there wouldn't be much hope of getting much done with this thing.


There's the aperture mechanism. It's nice that it's an easily removed module but not nice that you still have to take the mirror box out. But i'm not sure if these have the same failure issues.


An interesting feature is the film gate being moulded into the plastic body, doing a good job to hide any seam lines on the user visible side.


Anyways here's the thing I was after. I did look at the viewfinder LCD in the 7000i to see if that had an already sized zebra strip in it, but that was just more heat seal stuff.


I'd been pacing around thinking about clever and elaborate ways to cut a zebra strip but it turns out just a sharp scalpel goes right through it without issue. The donor LCD's glass edge was used as the cutting ruler. I used other parts from the camera to hold it in place and shim things up so the 'ruler' was gripping the rubber but not distorting it too much. The plastic diffuser there was just to keep the edge straight when lining things up, and moved out the way during the cut. I just estimated the cut thickness by eye at around 0.5mm. Also I made a second cut since the original edge was possibly a little deformed from years in contact with the LCD's traces.


And yeah that went back together and the segments are working fine. I'm fairly confident the zebra strip will maintain a good connection so I dolloped some epoxy around... and it aughta be cured enough for reassembly by now.


Edit: So much for 15 minute epoxy. It's JB Weld branded stuff. Hopefully it hasn't gone bad already. But it might just be because the dollops are so small. I'm happy to wait though, it's feeling like a real rigamarole by now and I don't really want to do it again.

The cameras back together. Got a fright thinking the autofocus was now going weird but it was just the atrocious minimal focus distance of the 28-135mm lens.

I'm fairly sure this LCD connection will be more robust. It's like known stuff, zebra strips. I wasn't sure what to expect from that tape or how it really behaves. I've concluded the camera fixed so many times at this point that i've ran out of things to say to try cap it off, lol. I need to actually take some photos with it, but I wanna get the NiCd battery back together for that. It'd also give me time to let it sit and see if any problems occur before I've put film in it.

What about the aperture magnet on the 9000?

Have you been able to identify the cause of the malfunction?

Is it primarily contamination?

Sooner or later, all of my 9000s will be affected by the sticky damper in the shutter, or already are. That's why I don't use any for photography yet, as incorrect exposures are likely.

So my next project will be to remove the mirror box and try to fit the shutter with a new damper. I'm using foam for mirror shock absorbers, which is self-adhesive.

I'll also clean the aperture magnet. Then document the assembly.

Together with the adjustment of the mirror (due to wear and tear on a damper in the mirror box), three out of four problems would then be solved.

The occasional blocking of the mechanism of the shutter and mirror box is still an open question.

With the 7000, I hope to verify my shortcut for the aperture magnet.

I don't see any more tasks for the two sisters, it's enough as it is.

Andreas Thaler said:

What about the aperture magnet on the 9000?

Have you been able to identify the cause of the malfunction?

Is it primarily contamination?

Click to expand...

Yeah removing the contaminants more thoroughly and slightly scuffing the contact surface of the non-electromagnet half with some 600 grit abrasive paper, just to take the polish off, seems to be working. I'm still hesitant to declare it a long term repair but it's definitely improved things.

For the shutter dampers you might want something a bit more robust than foam since the sharp edge of the shutter blades are slamming into it. I could see that causing the foam to turn to powder after a while. Maybe some variety of silicone mat could be an available source of rubber? There's a whole world of silicone kitchen utensils, i'm sure something would have to feature ~1mm thick rubber. Years ago I was getting bits of rubber from this silicone clad spatula i'd bought that had a metal core.

N

ogtronix said:

Yeah removing the contaminants more thoroughly and slightly scuffing the contact surface of the non-electromagnet half with some 600 grit abrasive paper, just to take the polish off, seems to be working. I'm still hesitant to declare it a long term repair but it's definitely improved things.

For the shutter dampers you might want something a bit more robust than foam since the sharp edge of the shutter blades are slamming into it. I could see that causing the foam to turn to powder after a while. Maybe some variety of silicone mat could be an available source of rubber? There's a whole world of silicone kitchen utensils, i'm sure something would have to feature ~1mm thick rubber. Years ago I was getting bits of rubber from this silicone clad spatula i'd bought that had a metal core.

Click to expand...

Excellent!

Thanks, I'll see what I can find in my stash.

To remove the rotten damper, should it be enough to remove the shutter unit and take off the rear frame? The fine springs on the right side can stay?